20400625 has 20 divisors (see below), whose sum is σ = 29140672. Its totient is φ = 13986000.

The previous prime is 20400599. The next prime is 20400631. The reversal of 20400625 is 52600402.

It is not a de Polignac number, because 20400625 - 2¹¹ = 20398577 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2044 + ... + 6706.

Almost surely, 2^20400625 is an apocalyptic number.

20400625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20400625 is a deficient number, since it is larger than the sum of its proper divisors (8740047).

20400625 is an frugal number, since it uses more digits than its factorization.

20400625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4690 (or 4675 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20400625 is about 4516.7051043875. The cubic root of 20400625 is about 273.2422320164.

It can be divided in two parts, 20400 and 625, that added together give a square (21025 = 145²).

The spelling of 20400625 in words is "twenty million, four hundred thousand, six hundred twenty-five".