21979130 has 16 divisors (see below), whose sum is σ = 41889960. Its totient is φ = 8274432.

The previous prime is 21979121. The next prime is 21979151. The reversal of 21979130 is 3197912.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20584369 + 1394761 = 4537^2 + 1181^2 .

It is a cake number, because a cake can be divided into 21979130 parts by 509 planar cuts.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64475 + ... + 64814.

Almost surely, 2^21979130 is an apocalyptic number.

21979130 is a deficient number, since it is larger than the sum of its proper divisors (19910830).

21979130 is a wasteful number, since it uses less digits than its factorization.

21979130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129313.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 21979130 is about 4688.1904824783. The cubic root of 21979130 is about 280.1153011531.

The spelling of 21979130 in words is "twenty-one million, nine hundred seventy-nine thousand, one hundred thirty".