21451764207 has 16 divisors (see below), whose sum is σ = 29415905792. Its totient is φ = 13895465760.

The previous prime is 21451764197. The next prime is 21451764227. The reversal of 21451764207 is 70246715412.

It is not a de Polignac number, because 21451764207 - 2⁸ = 21451763951 is a prime.

It is a super-3 number, since 3×21451764207³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21451764227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52219 + ... + 213612.

It is an arithmetic number, because the mean of its divisors is an integer number (1838494112).

Almost surely, 2^21451764207 is an apocalyptic number.

21451764207 is a deficient number, since it is larger than the sum of its proper divisors (7964141585).

21451764207 is a wasteful number, since it uses less digits than its factorization.

21451764207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266598.

The product of its (nonzero) digits is 94080, while the sum is 39.

The spelling of 21451764207 in words is "twenty-one billion, four hundred fifty-one million, seven hundred sixty-four thousand, two hundred seven".