20402407 has 2 divisors, whose sum is σ = 20402408. Its totient is φ = 20402406.

The previous prime is 20402387. The next prime is 20402411. The reversal of 20402407 is 70420402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20402407 - 2¹⁵ = 20369639 is a prime.

It is a super-2 number, since 2×20402407² = 832516422787298, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20402467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201203 + 10201204.

It is an arithmetic number, because the mean of its divisors is an integer number (10201204).

Almost surely, 2^20402407 is an apocalyptic number.

20402407 is a deficient number, since it is larger than the sum of its proper divisors (1).

20402407 is an equidigital number, since it uses as much as digits as its factorization.

20402407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 19.

The square root of 20402407 is about 4516.9023677737. The cubic root of 20402407 is about 273.2501877119.

Adding to 20402407 its reverse (70420402), we get a palindrome (90822809).

The spelling of 20402407 in words is "twenty million, four hundred two thousand, four hundred seven".