20951477 has 2 divisors, whose sum is σ = 20951478. Its totient is φ = 20951476.

The previous prime is 20951473. The next prime is 20951507. The reversal of 20951477 is 77415902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13060996 + 7890481 = 3614^2 + 2809^2 .

It is a cyclic number.

It is not a de Polignac number, because 20951477 - 2² = 20951473 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20951473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10475738 + 10475739.

It is an arithmetic number, because the mean of its divisors is an integer number (10475739).

Almost surely, 2^20951477 is an apocalyptic number.

It is an amenable number.

20951477 is a deficient number, since it is larger than the sum of its proper divisors (1).

20951477 is an equidigital number, since it uses as much as digits as its factorization.

20951477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 20951477 is about 4577.2783397998. The cubic root of 20951477 is about 275.6797596716.

The spelling of 20951477 in words is "twenty million, nine hundred fifty-one thousand, four hundred seventy-seven".