1615630451891 has 2 divisors, whose sum is σ = 1615630451892. Its totient is φ = 1615630451890.

The previous prime is 1615630451887. The next prime is 1615630451899. The reversal of 1615630451891 is 1981540365161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1615630451891 - 2² = 1615630451887 is a prime.

It is a super-2 number, since 2×1615630451891² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1615630451899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 807815225945 + 807815225946.

It is an arithmetic number, because the mean of its divisors is an integer number (807815225946).

Almost surely, 2^{1615630451891} is an apocalyptic number.

1615630451891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1615630451891 is an equidigital number, since it uses as much as digits as its factorization.

1615630451891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 777600, while the sum is 50.

The spelling of 1615630451891 in words is "one trillion, six hundred fifteen billion, six hundred thirty million, four hundred fifty-one thousand, eight hundred ninety-one".