20615561424 has 50 divisors (see below), whose sum is σ = 59667419570. Its totient is φ = 6871853376.

The previous prime is 20615561413. The next prime is 20615561429. The reversal of 20615561424 is 42416551602.

20615561424 is a `hidden beast` number, since 2 + 0 + 6 + 15 + 5 + 614 + 24 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13579707024 + 7035854400 = 116532^2 + 83880^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20615561429) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 7952239 + ... + 7954830.

Almost surely, 2^20615561424 is an apocalyptic number.

20615561424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20615561424 is an abundant number, since it is smaller than the sum of its proper divisors (39051858146).

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

20615561424 is a wasteful number, since it uses less digits than its factorization.

20615561424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15907089 (or 15907074 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 20615561424 in words is "twenty billion, six hundred fifteen million, five hundred sixty-one thousand, four hundred twenty-four".