39920121951 has 16 divisors (see below), whose sum is σ = 54581361408. Its totient is φ = 25937489600.

The previous prime is 39920121929. The next prime is 39920121977. The reversal of 39920121951 is 15912102993.

It is a cyclic number.

It is not a de Polignac number, because 39920121951 - 2¹⁰ = 39920120927 is a prime.

It is a super-2 number, since 2×39920121951² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39920121991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47691 + ... + 286556.

It is an arithmetic number, because the mean of its divisors is an integer number (3411335088).

Almost surely, 2^39920121951 is an apocalyptic number.

39920121951 is a deficient number, since it is larger than the sum of its proper divisors (14661239457).

39920121951 is a wasteful number, since it uses less digits than its factorization.

39920121951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335262.

The product of its (nonzero) digits is 43740, while the sum is 42.

The spelling of 39920121951 in words is "thirty-nine billion, nine hundred twenty million, one hundred twenty-one thousand, nine hundred fifty-one".