61557100 has 72 divisors (see below), whose sum is σ = 147365568. Its totient is φ = 22132800.

The previous prime is 61557091. The next prime is 61557101. The reversal of 61557100 is 175516.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (61557101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 117439 + ... + 117961.

It is an arithmetic number, because the mean of its divisors is an integer number (2046744).

Almost surely, 2^61557100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61557100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73682784).

61557100 is an abundant number, since it is smaller than the sum of its proper divisors (85808468).

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

61557100 is a wasteful number, since it uses less digits than its factorization.

61557100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655 (or 648 counting only the distinct ones).

The product of its (nonzero) digits is 1050, while the sum is 25.

The square root of 61557100 is about 7845.8332890777. The cubic root of 61557100 is about 394.8444615414.

The spelling of 61557100 in words is "sixty-one million, five hundred fifty-seven thousand, one hundred".