21031629 has 4 divisors (see below), whose sum is σ = 28042176. Its totient is φ = 14021084.

The previous prime is 21031627. The next prime is 21031639. The reversal of 21031629 is 92613012.

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 21031629 - 2¹ = 21031627 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21031599 and 21031608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3505269 + ... + 3505274.

It is an arithmetic number, because the mean of its divisors is an integer number (7010544).

Almost surely, 2^21031629 is an apocalyptic number.

It is an amenable number.

21031629 is a deficient number, since it is larger than the sum of its proper divisors (7010547).

21031629 is an equidigital number, since it uses as much as digits as its factorization.

21031629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7010546.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 21031629 is about 4586.0254033313. The cubic root of 21031629 is about 276.0308592884.

The spelling of 21031629 in words is "twenty-one million, thirty-one thousand, six hundred twenty-nine".