40345721691 has 32 divisors (see below), whose sum is σ = 59416955136. Its totient is φ = 24148080000.

The previous prime is 40345721681. The next prime is 40345721693. The reversal of 40345721691 is 19612754304.

It is a de Polignac number, because none of the positive numbers 2^k-40345721691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40345721693) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1307956 + ... + 1338446.

It is an arithmetic number, because the mean of its divisors is an integer number (1856779848).

Almost surely, 2^40345721691 is an apocalyptic number.

40345721691 is a deficient number, since it is larger than the sum of its proper divisors (19071233445).

40345721691 is a wasteful number, since it uses less digits than its factorization.

40345721691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31003.

The product of its (nonzero) digits is 181440, while the sum is 42.

The spelling of 40345721691 in words is "forty billion, three hundred forty-five million, seven hundred twenty-one thousand, six hundred ninety-one".