51619920 has 80 divisors (see below), whose sum is σ = 174578112. Its totient is φ = 12513280.

The previous prime is 51619891. The next prime is 51619927. The reversal of 51619920 is 2991615.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×51619920² = 5329232281612800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51619927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7137 + ... + 12416.

Almost surely, 2^51619920 is an apocalyptic number.

It is an amenable number.

51619920 is an abundant number, since it is smaller than the sum of its proper divisors (122958192).

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

51619920 is a wasteful number, since it uses less digits than its factorization.

51619920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19580 (or 19574 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 51619920 is about 7184.7004112906. The cubic root of 51619920 is about 372.3394981401.

The spelling of 51619920 in words is "fifty-one million, six hundred nineteen thousand, nine hundred twenty".