61557740 has 24 divisors (see below), whose sum is σ = 130727520. Its totient is φ = 24345728.

The previous prime is 61557721. The next prime is 61557763. The reversal of 61557740 is 4775516.

It is a self number, because there is not a number n which added to its sum of digits gives 61557740.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15512 + ... + 19071.

It is an arithmetic number, because the mean of its divisors is an integer number (5446980).

Almost surely, 2^61557740 is an apocalyptic number.

It is an amenable number.

61557740 is an abundant number, since it is smaller than the sum of its proper divisors (69169780).

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

61557740 is a wasteful number, since it uses less digits than its factorization.

61557740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34681 (or 34679 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 35.

The square root of 61557740 is about 7845.8740749518. The cubic root of 61557740 is about 394.8458299163.

The spelling of 61557740 in words is "sixty-one million, five hundred fifty-seven thousand, seven hundred forty".