20657151578 has 24 divisors (see below), whose sum is σ = 37018807092. Its totient is φ = 8613791424.

The previous prime is 20657151527. The next prime is 20657151583. The reversal of 20657151578 is 87515175602.

It can be written as a sum of positive squares in 2 ways, for example, as 19037652529 + 1619499049 = 137977^2 + 40243^2 .

It is a super-2 number, since 2×20657151578² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2844851 + ... + 2852102.

Almost surely, 2^20657151578 is an apocalyptic number.

20657151578 is a deficient number, since it is larger than the sum of its proper divisors (16361655514).

20657151578 is a wasteful number, since it uses less digits than its factorization.

20657151578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5697006 (or 5696999 counting only the distinct ones).

The product of its (nonzero) digits is 588000, while the sum is 47.

The spelling of 20657151578 in words is "twenty billion, six hundred fifty-seven million, one hundred fifty-one thousand, five hundred seventy-eight".