20531730 has 32 divisors (see below), whose sum is σ = 49486464. Its totient is φ = 5451776.

The previous prime is 20531717. The next prime is 20531741. The reversal of 20531730 is 3713502.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20531697 and 20531706.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6379 + ... + 9041.

It is an arithmetic number, because the mean of its divisors is an integer number (1546452).

Almost surely, 2^20531730 is an apocalyptic number.

20531730 is an abundant number, since it is smaller than the sum of its proper divisors (28954734).

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

20531730 is a wasteful number, since it uses less digits than its factorization.

20531730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2930.

The product of its (nonzero) digits is 630, while the sum is 21.

The square root of 20531730 is about 4531.1952065653. The cubic root of 20531730 is about 273.8263147047.

The spelling of 20531730 in words is "twenty million, five hundred thirty-one thousand, seven hundred thirty".