20402051 has 8 divisors (see below), whose sum is σ = 21621600. Its totient is φ = 19216960.

The previous prime is 20402021. The next prime is 20402087. The reversal of 20402051 is 15020402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20402051 - 2²² = 16207747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20402021) 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, 7391 + ... + 9768.

It is an arithmetic number, because the mean of its divisors is an integer number (2702700).

Almost surely, 2^20402051 is an apocalyptic number.

20402051 is a deficient number, since it is larger than the sum of its proper divisors (1219549).

20402051 is a wasteful number, since it uses less digits than its factorization.

20402051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17229.

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 20402051 is about 4516.8629600642. The cubic root of 20402051 is about 273.2485983956.

Adding to 20402051 its reverse (15020402), we get a palindrome (35422453).

The spelling of 20402051 in words is "twenty million, four hundred two thousand, fifty-one".