12540421971 has 288 divisors, whose sum is σ = 25944576000. Its totient is φ = 5972551200.

The previous prime is 12540421939. The next prime is 12540421979. The reversal of 12540421971 is 17912404521.

12540421971 = T₂₅₁ + T₂₅₂ + ... + T₄₂₂₁.

12540421971 is a `hidden beast` number, since 1 + 2 + 540 + 4 + 21 + 97 + 1 = 666.

It is not a de Polignac number, because 12540421971 - 2⁵ = 12540421939 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12540421979) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 404529726 + ... + 404529756.

Almost surely, 2^12540421971 is an apocalyptic number.

12540421971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12540421971 is an abundant number, since it is smaller than the sum of its proper divisors (13404154029).

12540421971 is a wasteful number, since it uses less digits than its factorization.

12540421971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 12540421971 in words is "twelve billion, five hundred forty million, four hundred twenty-one thousand, nine hundred seventy-one".