1620908694931 has 2 divisors, whose sum is σ = 1620908694932. Its totient is φ = 1620908694930.

The previous prime is 1620908694883. The next prime is 1620908694953. The reversal of 1620908694931 is 1394968090261.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1620908694931 is a prime.

It is a super-2 number, since 2×1620908694931² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1620908694971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810454347465 + 810454347466.

It is an arithmetic number, because the mean of its divisors is an integer number (810454347466).

Almost surely, 2^{1620908694931} is an apocalyptic number.

1620908694931 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620908694931 is an equidigital number, since it uses as much as digits as its factorization.

1620908694931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5038848, while the sum is 58.

The spelling of 1620908694931 in words is "one trillion, six hundred twenty billion, nine hundred eight million, six hundred ninety-four thousand, nine hundred thirty-one".