21777157060 has 24 divisors (see below), whose sum is σ = 46358499096. Its totient is φ = 8591535360.

The previous prime is 21777157057. The next prime is 21777157069. The reversal of 21777157060 is 6075177712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 64545156 + 21712611904 = 8034^2 + 147352^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21777156998 and 21777157016.

It is not an unprimeable number, because it can be changed into a prime (21777157069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7456471 + ... + 7459390.

It is an arithmetic number, because the mean of its divisors is an integer number (1931604129).

Almost surely, 2^21777157060 is an apocalyptic number.

21777157060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21777157060 is an abundant number, since it is smaller than the sum of its proper divisors (24581342036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21777157060 is a wasteful number, since it uses less digits than its factorization.

21777157060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14915943 (or 14915941 counting only the distinct ones).

The product of its (nonzero) digits is 144060, while the sum is 43.

The spelling of 21777157060 in words is "twenty-one billion, seven hundred seventy-seven million, one hundred fifty-seven thousand, sixty".