20731020177621 has 16 divisors (see below), whose sum is σ = 30062347620480. Its totient is φ = 12631238491200.

The previous prime is 20731020177619. The next prime is 20731020177629. The reversal of 20731020177621 is 12677102013702.

It is not a de Polignac number, because 20731020177621 - 2¹ = 20731020177619 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 20731020177621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731020177629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2631504081 + ... + 2631511958.

It is an arithmetic number, because the mean of its divisors is an integer number (1878896726280).

Almost surely, 2^{20731020177621} is an apocalyptic number.

It is an amenable number.

20731020177621 is a deficient number, since it is larger than the sum of its proper divisors (9331327442859).

20731020177621 is a wasteful number, since it uses less digits than its factorization.

20731020177621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5263016156.

The product of its (nonzero) digits is 49392, while the sum is 39.

The spelling of 20731020177621 in words is "twenty trillion, seven hundred thirty-one billion, twenty million, one hundred seventy-seven thousand, six hundred twenty-one".