642297780 has 54 divisors (see below), whose sum is σ = 1949335206. Its totient is φ = 171188736.

The previous prime is 642297769. The next prime is 642297787. The reversal of 642297780 is 87792246.

642297780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 57335184 + 584962596 = 7572^2 + 24186^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642297787) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 339076 + ... + 340964.

Almost surely, 2^642297780 is an apocalyptic number.

642297780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642297780 is an abundant number, since it is smaller than the sum of its proper divisors (1307037426).

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

642297780 is a wasteful number, since it uses less digits than its factorization.

642297780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3793 (or 1899 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 642297780 is about 25343.5944569826. The cubic root of 642297780 is about 862.8039810685.

Multiplying 642297780 by its sum of digits (45), we get a square (28903400100 = 170010²).

642297780 divided by its sum of digits (45) gives a square (14273284 = 3778²).

The spelling of 642297780 in words is "six hundred forty-two million, two hundred ninety-seven thousand, seven hundred eighty".