61569690 has 128 divisors (see below), whose sum is σ = 191600640. Its totient is φ = 12296448.

The previous prime is 61569667. The next prime is 61569691. The reversal of 61569690 is 9696516.

It is a super-2 number, since 2×61569690² = 7581653453392200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (61569691) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 51277 + ... + 52463.

It is an arithmetic number, because the mean of its divisors is an integer number (1496880).

Almost surely, 2^61569690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61569690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95800320).

61569690 is an abundant number, since it is smaller than the sum of its proper divisors (130030950).

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

61569690 is a wasteful number, since it uses less digits than its factorization.

61569690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1236.

The product of its (nonzero) digits is 87480, while the sum is 42.

The square root of 61569690 is about 7846.6355847586. The cubic root of 61569690 is about 394.8713783006.

The spelling of 61569690 in words is "sixty-one million, five hundred sixty-nine thousand, six hundred ninety".