61491521625 has 48 divisors (see below), whose sum is σ = 107990932608. Its totient is φ = 31069332000.

The previous prime is 61491521563. The next prime is 61491521633. The reversal of 61491521625 is 52612519416.

It is a happy number.

It is not a de Polignac number, because 61491521625 - 2⁸ = 61491521369 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 91741 + ... + 362490.

It is an arithmetic number, because the mean of its divisors is an integer number (2249811096).

Almost surely, 2^61491521625 is an apocalyptic number.

It is an amenable number.

61491521625 is a deficient number, since it is larger than the sum of its proper divisors (46499410983).

61491521625 is a wasteful number, since it uses less digits than its factorization.

61491521625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454287 (or 454258 counting only the distinct ones).

The product of its digits is 129600, while the sum is 42.

The spelling of 61491521625 in words is "sixty-one billion, four hundred ninety-one million, five hundred twenty-one thousand, six hundred twenty-five".