61809972 has 48 divisors (see below), whose sum is σ = 168201600. Its totient is φ = 17658816.

The previous prime is 61809967. The next prime is 61810003. The reversal of 61809972 is 27990816.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3393 + ... + 11624.

It is an arithmetic number, because the mean of its divisors is an integer number (3504200).

Almost surely, 2^61809972 is an apocalyptic number.

It is an amenable number.

61809972 is an abundant number, since it is smaller than the sum of its proper divisors (106391628).

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

61809972 is a wasteful number, since it uses less digits than its factorization.

61809972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15045 (or 15029 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 61809972 is about 7861.9318236678. The cubic root of 61809972 is about 395.3843868090.

The spelling of 61809972 in words is "sixty-one million, eight hundred nine thousand, nine hundred seventy-two".