21620157043637 has 2 divisors, whose sum is σ = 21620157043638. Its totient is φ = 21620157043636.

The previous prime is 21620157043613. The next prime is 21620157043669. The reversal of 21620157043637 is 73634075102612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12447411991921 + 9172745051716 = 3528089^2 + 3028654^2 .

It is a cyclic number.

It is not a de Polignac number, because 21620157043637 - 2¹² = 21620157039541 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21620157043591 and 21620157043600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21620157043337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10810078521818 + 10810078521819.

It is an arithmetic number, because the mean of its divisors is an integer number (10810078521819).

Almost surely, 2^{21620157043637} is an apocalyptic number.

It is an amenable number.

21620157043637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21620157043637 is an equidigital number, since it uses as much as digits as its factorization.

21620157043637 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1270080, while the sum is 47.

The spelling of 21620157043637 in words is "twenty-one trillion, six hundred twenty billion, one hundred fifty-seven million, forty-three thousand, six hundred thirty-seven".