21294651 has 16 divisors (see below), whose sum is σ = 32514048. Its totient is φ = 12144000.

The previous prime is 21294641. The next prime is 21294653. The reversal of 21294651 is 15649212.

It is not a de Polignac number, because 21294651 - 2⁶ = 21294587 is a prime.

It is a super-2 number, since 2×21294651² = 906924322423602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21294653) 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, 17926 + ... + 19076.

It is an arithmetic number, because the mean of its divisors is an integer number (2032128).

Almost surely, 2^21294651 is an apocalyptic number.

21294651 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21294651 is a deficient number, since it is larger than the sum of its proper divisors (11219397).

21294651 is a wasteful number, since it uses less digits than its factorization.

21294651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2042.

The product of its digits is 4320, while the sum is 30.

The square root of 21294651 is about 4614.6127681529. The cubic root of 21294651 is about 277.1767781209.

It can be divided in two parts, 21294 and 651, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21294651 in words is "twenty-one million, two hundred ninety-four thousand, six hundred fifty-one".