61554640 has 40 divisors (see below), whose sum is σ = 163560960. Its totient is φ = 21104256.

The previous prime is 61554613. The next prime is 61554707. The reversal of 61554640 is 4645516.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

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, 54400 + ... + 55519.

It is an arithmetic number, because the mean of its divisors is an integer number (4089024).

Almost surely, 2^61554640 is an apocalyptic number.

It is an amenable number.

61554640 is an abundant number, since it is smaller than the sum of its proper divisors (102006320).

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

61554640 is a wasteful number, since it uses less digits than its factorization.

61554640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109939 (or 109933 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 61554640 is about 7845.6765164006. The cubic root of 61554640 is about 394.8392017619.

It can be divided in two parts, 615 and 54640, that added together give a palindrome (55255).

The spelling of 61554640 in words is "sixty-one million, five hundred fifty-four thousand, six hundred forty".