61507997 has 4 divisors (see below), whose sum is σ = 64745280. Its totient is φ = 58270716.

The previous prime is 61507993. The next prime is 61508009. The reversal of 61507997 is 79970516.

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 61507997 - 2² = 61507993 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61507993) 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, 1618613 + ... + 1618650.

It is an arithmetic number, because the mean of its divisors is an integer number (16186320).

Almost surely, 2^61507997 is an apocalyptic number.

It is an amenable number.

61507997 is a deficient number, since it is larger than the sum of its proper divisors (3237283).

61507997 is a wasteful number, since it uses less digits than its factorization.

61507997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3237282.

The product of its (nonzero) digits is 119070, while the sum is 44.

The square root of 61507997 is about 7842.7034242027. The cubic root of 61507997 is about 394.7394468204.

The spelling of 61507997 in words is "sixty-one million, five hundred seven thousand, nine hundred ninety-seven".