21631434 has 32 divisors (see below), whose sum is σ = 47485440. Its totient is φ = 6514800.

The previous prime is 21631409. The next prime is 21631439. The reversal of 21631434 is 43413612.

It is not an unprimeable number, because it can be changed into a prime (21631439) 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, 10899 + ... + 12729.

It is an arithmetic number, because the mean of its divisors is an integer number (1483920).

Almost surely, 2^21631434 is an apocalyptic number.

21631434 is an abundant number, since it is smaller than the sum of its proper divisors (25854006).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21631434 is a wasteful number, since it uses less digits than its factorization.

21631434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2026.

The product of its digits is 1728, while the sum is 24.

The square root of 21631434 is about 4650.9605459518. The cubic root of 21631434 is about 278.6303605573.

The spelling of 21631434 in words is "twenty-one million, six hundred thirty-one thousand, four hundred thirty-four".