99720457 has 4 divisors (see below), whose sum is σ = 99783376. Its totient is φ = 99657540.

The previous prime is 99720449. The next prime is 99720463. The reversal of 99720457 is 75402799.

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 99720457 - 2³ = 99720449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99720497) 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, 29019 + ... + 32272.

It is an arithmetic number, because the mean of its divisors is an integer number (24945844).

Almost surely, 2^99720457 is an apocalyptic number.

It is an amenable number.

99720457 is a deficient number, since it is larger than the sum of its proper divisors (62919).

99720457 is a wasteful number, since it uses less digits than its factorization.

99720457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62918.

The product of its (nonzero) digits is 158760, while the sum is 43.

The square root of 99720457 is about 9986.0130682871. The cubic root of 99720457 is about 463.7259718299.

The spelling of 99720457 in words is "ninety-nine million, seven hundred twenty thousand, four hundred fifty-seven".