21001000631 has 8 divisors (see below), whose sum is σ = 22679465760. Its totient is φ = 19331536032.

The previous prime is 21001000613. The next prime is 21001000651. The reversal of 21001000631 is 13600010012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001000631 is a prime.

It is a super-2 number, since 2×21001000631² (a number of 21 digits) contains 22 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 (21001000651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2245280 + ... + 2254613.

It is an arithmetic number, because the mean of its divisors is an integer number (2834933220).

Almost surely, 2^21001000631 is an apocalyptic number.

21001000631 is a deficient number, since it is larger than the sum of its proper divisors (1678465129).

21001000631 is a wasteful number, since it uses less digits than its factorization.

21001000631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4500265.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21001000631 its reverse (13600010012), we get a palindrome (34601010643).

The spelling of 21001000631 in words is "twenty-one billion, one million, six hundred thirty-one", and thus it is an aban number.