1621615606157 has 2 divisors, whose sum is σ = 1621615606158. Its totient is φ = 1621615606156.

The previous prime is 1621615606111. The next prime is 1621615606183. The reversal of 1621615606157 is 7516065161261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1599906235876 + 21709370281 = 1264874^2 + 147341^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621615606157 - 2²² = 1621611411853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1621615606357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810807803078 + 810807803079.

It is an arithmetic number, because the mean of its divisors is an integer number (810807803079).

Almost surely, 2^{1621615606157} is an apocalyptic number.

It is an amenable number.

1621615606157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621615606157 is an equidigital number, since it uses as much as digits as its factorization.

1621615606157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 453600, while the sum is 47.

The spelling of 1621615606157 in words is "one trillion, six hundred twenty-one billion, six hundred fifteen million, six hundred six thousand, one hundred fifty-seven".