21777153131 has 2 divisors, whose sum is σ = 21777153132. Its totient is φ = 21777153130.

The previous prime is 21777153121. The next prime is 21777153161. The reversal of 21777153131 is 13135177712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21777153131 is a prime.

It is a super-2 number, since 2×21777153131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21777153121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10888576565 + 10888576566.

It is an arithmetic number, because the mean of its divisors is an integer number (10888576566).

Almost surely, 2^21777153131 is an apocalyptic number.

21777153131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21777153131 is an equidigital number, since it uses as much as digits as its factorization.

21777153131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30870, while the sum is 38.

The spelling of 21777153131 in words is "twenty-one billion, seven hundred seventy-seven million, one hundred fifty-three thousand, one hundred thirty-one".