40542539621 has 2 divisors, whose sum is σ = 40542539622. Its totient is φ = 40542539620.

The previous prime is 40542539593. The next prime is 40542539647. The reversal of 40542539621 is 12693524504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32699488900 + 7843050721 = 180830^2 + 88561^2 .

It is a cyclic number.

It is not a de Polignac number, because 40542539621 - 2³⁴ = 23362670437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40542559621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20271269810 + 20271269811.

It is an arithmetic number, because the mean of its divisors is an integer number (20271269811).

Almost surely, 2^40542539621 is an apocalyptic number.

It is an amenable number.

40542539621 is a deficient number, since it is larger than the sum of its proper divisors (1).

40542539621 is an equidigital number, since it uses as much as digits as its factorization.

40542539621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 40542539621 in words is "forty billion, five hundred forty-two million, five hundred thirty-nine thousand, six hundred twenty-one".