61851408021 has 48 divisors (see below), whose sum is σ = 98319451776. Its totient is φ = 37238133888.

The previous prime is 61851407987. The next prime is 61851408053. The reversal of 61851408021 is 12080415816.

61851408021 is a `hidden beast` number, since 61 + 8 + 514 + 0 + 80 + 2 + 1 = 666.

61851408021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61851408021 - 2⁹ = 61851407509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61851408121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 969315 + ... + 1031151.

It is an arithmetic number, because the mean of its divisors is an integer number (2048321912).

Almost surely, 2^61851408021 is an apocalyptic number.

It is an amenable number.

61851408021 is a deficient number, since it is larger than the sum of its proper divisors (36468043755).

61851408021 is a wasteful number, since it uses less digits than its factorization.

61851408021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62042 (or 62039 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The spelling of 61851408021 in words is "sixty-one billion, eight hundred fifty-one million, four hundred eight thousand, twenty-one".