20621479 has 16 divisors (see below), whose sum is σ = 22650880. Its totient is φ = 18701280.

The previous prime is 20621443. The next prime is 20621519. The reversal of 20621479 is 97412602.

It is a cyclic number.

It is not a de Polignac number, because 20621479 - 2⁷ = 20621351 is a prime.

It is a super-2 number, since 2×20621479² = 850490792294882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20621479.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20624479) 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, 92362 + ... + 92584.

It is an arithmetic number, because the mean of its divisors is an integer number (1415680).

Almost surely, 2^20621479 is an apocalyptic number.

20621479 is a deficient number, since it is larger than the sum of its proper divisors (2029401).

20621479 is a wasteful number, since it uses less digits than its factorization.

20621479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20621479 is about 4541.0878652587. The cubic root of 20621479 is about 274.2247210738.

The spelling of 20621479 in words is "twenty million, six hundred twenty-one thousand, four hundred seventy-nine".