40001999971 has 2 divisors, whose sum is σ = 40001999972. Its totient is φ = 40001999970.

The previous prime is 40001999867. The next prime is 40001999977. The reversal of 40001999971 is 17999910004.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40001999971 - 2²¹ = 39999902819 is a prime.

It is not a weakly prime, because it can be changed into another prime (40001999977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20000999985 + 20000999986.

It is an arithmetic number, because the mean of its divisors is an integer number (20000999986).

Almost surely, 2^40001999971 is an apocalyptic number.

40001999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

40001999971 is an equidigital number, since it uses as much as digits as its factorization.

40001999971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 183708, while the sum is 49.

The spelling of 40001999971 in words is "forty billion, one million, nine hundred ninety-nine thousand, nine hundred seventy-one".