20402402357 has 4 divisors (see below), whose sum is σ = 20411233056. Its totient is φ = 20393571660.

The previous prime is 20402402351. The next prime is 20402402381. The reversal of 20402402357 is 75320420402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20402402357 - 2³² = 16107435061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402402351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4411883 + ... + 4416504.

It is an arithmetic number, because the mean of its divisors is an integer number (5102808264).

Almost surely, 2^20402402357 is an apocalyptic number.

It is an amenable number.

20402402357 is a deficient number, since it is larger than the sum of its proper divisors (8830699).

20402402357 is an equidigital number, since it uses as much as digits as its factorization.

20402402357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8830698.

The product of its (nonzero) digits is 13440, while the sum is 29.

Adding to 20402402357 its reverse (75320420402), we get a palindrome (95722822759).

The spelling of 20402402357 in words is "twenty billion, four hundred two million, four hundred two thousand, three hundred fifty-seven".