21396861037 has 4 divisors (see below), whose sum is σ = 21402876640. Its totient is φ = 21390845436.

The previous prime is 21396860983. The next prime is 21396861049. The reversal of 21396861037 is 73016869312.

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 21396861037 - 2¹⁹ = 21396336749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21396861737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3002463 + ... + 3009580.

It is an arithmetic number, because the mean of its divisors is an integer number (5350719160).

Almost surely, 2^21396861037 is an apocalyptic number.

It is an amenable number.

21396861037 is a deficient number, since it is larger than the sum of its proper divisors (6015603).

21396861037 is an equidigital number, since it uses as much as digits as its factorization.

21396861037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6015602.

The product of its (nonzero) digits is 326592, while the sum is 46.

The spelling of 21396861037 in words is "twenty-one billion, three hundred ninety-six million, eight hundred sixty-one thousand, thirty-seven".