90129780 has 192 divisors, whose sum is σ = 311028480. Its totient is φ = 21523968.

The previous prime is 90129769. The next prime is 90129791. The reversal of 90129780 is 8792109.

90129780 = 170² + 171² + ... + 650².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (90129769) and next prime (90129791).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 259567 + ... + 259913.

It is an arithmetic number, because the mean of its divisors is an integer number (1619940).

Almost surely, 2^90129780 is an apocalyptic number.

90129780 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90129780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155514240).

90129780 is an abundant number, since it is smaller than the sum of its proper divisors (220898700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

90129780 is a wasteful number, since it uses less digits than its factorization.

90129780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 90129780 is about 9493.6705230380. The cubic root of 90129780 is about 448.3557773882.

It can be divided in two parts, 90129 and 780, that added together give a palindrome (90909).

The spelling of 90129780 in words is "ninety million, one hundred twenty-nine thousand, seven hundred eighty".