65720157 has 4 divisors (see below), whose sum is σ = 87626880. Its totient is φ = 43813436.

The previous prime is 65720153. The next prime is 65720191. The reversal of 65720157 is 75102756.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65720157 - 2² = 65720153 is a prime.

It is a super-2 number, since 2×65720157² = 8638278072209298, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65720153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10953357 + ... + 10953362.

It is an arithmetic number, because the mean of its divisors is an integer number (21906720).

Almost surely, 2^65720157 is an apocalyptic number.

It is an amenable number.

65720157 is a deficient number, since it is larger than the sum of its proper divisors (21906723).

65720157 is a wasteful number, since it uses less digits than its factorization.

65720157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21906722.

The product of its (nonzero) digits is 14700, while the sum is 33.

The square root of 65720157 is about 8106.7969630428. The cubic root of 65720157 is about 403.5520248498.

The spelling of 65720157 in words is "sixty-five million, seven hundred twenty thousand, one hundred fifty-seven".