40387929721 has 4 divisors (see below), whose sum is σ = 40536962944. Its totient is φ = 40238896500.

The previous prime is 40387929667. The next prime is 40387929727. The reversal of 40387929721 is 12792978304.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40387929721 - 2²⁹ = 39851058809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40387929727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74516205 + ... + 74516746.

It is an arithmetic number, because the mean of its divisors is an integer number (10134240736).

Almost surely, 2^40387929721 is an apocalyptic number.

It is an amenable number.

40387929721 is a deficient number, since it is larger than the sum of its proper divisors (149033223).

40387929721 is a wasteful number, since it uses less digits than its factorization.

40387929721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149033222.

The product of its (nonzero) digits is 1524096, while the sum is 52.

The spelling of 40387929721 in words is "forty billion, three hundred eighty-seven million, nine hundred twenty-nine thousand, seven hundred twenty-one".