61621518 has 24 divisors (see below), whose sum is σ = 143365032. Its totient is φ = 17606064.

The previous prime is 61621517. The next prime is 61621589. The reversal of 61621518 is 81512616.

It is a super-2 number, since 2×61621518² = 7594422961248648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61621517) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104505 + ... + 105092.

It is an arithmetic number, because the mean of its divisors is an integer number (5973543).

Almost surely, 2^61621518 is an apocalyptic number.

61621518 is an abundant number, since it is smaller than the sum of its proper divisors (81743514).

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

61621518 is a wasteful number, since it uses less digits than its factorization.

61621518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209616 (or 209609 counting only the distinct ones).

The product of its digits is 2880, while the sum is 30.

The square root of 61621518 is about 7849.9374519801. The cubic root of 61621518 is about 394.9821452165.

The spelling of 61621518 in words is "sixty-one million, six hundred twenty-one thousand, five hundred eighteen".