21426951 has 16 divisors (see below), whose sum is σ = 35162624. Its totient is φ = 11301984.

The previous prime is 21426931. The next prime is 21426973. The reversal of 21426951 is 15962412.

It is not a de Polignac number, because 21426951 - 2⁹ = 21426439 is a prime.

It is a super-2 number, since 2×21426951² = 918228458312802, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38971 + ... + 39516.

It is an arithmetic number, because the mean of its divisors is an integer number (2197664).

Almost surely, 2^21426951 is an apocalyptic number.

21426951 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21426951 is a deficient number, since it is larger than the sum of its proper divisors (13735673).

21426951 is a wasteful number, since it uses less digits than its factorization.

21426951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78510.

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

The square root of 21426951 is about 4628.9254692639. The cubic root of 21426951 is about 277.7496106491.

The spelling of 21426951 in words is "twenty-one million, four hundred twenty-six thousand, nine hundred fifty-one".