61664990850 has 48 divisors (see below), whose sum is σ = 169921311840. Its totient is φ = 16443997200.

The previous prime is 61664990839. The next prime is 61664990861. The reversal of 61664990850 is 5809946616.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (61664990839) and next prime (61664990861).

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22837536 + ... + 22840235.

It is an arithmetic number, because the mean of its divisors is an integer number (3540027330).

Almost surely, 2^61664990850 is an apocalyptic number.

61664990850 is an abundant number, since it is smaller than the sum of its proper divisors (108256320990).

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

61664990850 is a wasteful number, since it uses less digits than its factorization.

61664990850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45677792 (or 45677781 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The spelling of 61664990850 in words is "sixty-one billion, six hundred sixty-four million, nine hundred ninety thousand, eight hundred fifty".