1957121621 has 32 divisors (see below), whose sum is σ = 2459175936. Its totient is φ = 1516320000.

The previous prime is 1957121611. The next prime is 1957121633. The reversal of 1957121621 is 1261217591.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-1957121621 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1957121611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1503671 + ... + 1504971.

It is an arithmetic number, because the mean of its divisors is an integer number (76849248).

Almost surely, 2^1957121621 is an apocalyptic number.

It is an amenable number.

1957121621 is a deficient number, since it is larger than the sum of its proper divisors (502054315).

1957121621 is a wasteful number, since it uses less digits than its factorization.

1957121621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1653.

The product of its digits is 7560, while the sum is 35.

The square root of 1957121621 is about 44239.3673214254. The cubic root of 1957121621 is about 1250.8520315818.

The spelling of 1957121621 in words is "one billion, nine hundred fifty-seven million, one hundred twenty-one thousand, six hundred twenty-one".