21718778037 has 32 divisors (see below), whose sum is σ = 32461684224. Its totient is φ = 12800462400.

The previous prime is 21718777981. The next prime is 21718778047. The reversal of 21718778037 is 73087781712.

It is not a de Polignac number, because 21718778037 - 2⁸ = 21718777781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21718778047) 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, 3301962 + ... + 3308532.

It is an arithmetic number, because the mean of its divisors is an integer number (1014427632).

Almost surely, 2^21718778037 is an apocalyptic number.

It is an amenable number.

21718778037 is a deficient number, since it is larger than the sum of its proper divisors (10742906187).

21718778037 is a wasteful number, since it uses less digits than its factorization.

21718778037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9329.

The product of its (nonzero) digits is 921984, while the sum is 51.

The spelling of 21718778037 in words is "twenty-one billion, seven hundred eighteen million, seven hundred seventy-eight thousand, thirty-seven".