20978711431 has 2 divisors, whose sum is σ = 20978711432. Its totient is φ = 20978711430.

The previous prime is 20978711333. The next prime is 20978711443. The reversal of 20978711431 is 13411787902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20978711431 - 2¹⁵ = 20978678663 is a prime.

It is a super-2 number, since 2×20978711431² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20978715431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489355715 + 10489355716.

It is an arithmetic number, because the mean of its divisors is an integer number (10489355716).

Almost surely, 2^20978711431 is an apocalyptic number.

20978711431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20978711431 is an equidigital number, since it uses as much as digits as its factorization.

20978711431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 43.

The spelling of 20978711431 in words is "twenty billion, nine hundred seventy-eight million, seven hundred eleven thousand, four hundred thirty-one".