61820031 has 24 divisors (see below), whose sum is σ = 102011520. Its totient is φ = 32606496.

The previous prime is 61819997. The next prime is 61820039. The reversal of 61820031 is 13002816.

It is not a de Polignac number, because 61820031 - 2⁹ = 61819519 is a prime.

It is a super-2 number, since 2×61820031² = 7643432465681922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61820039) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5161 + ... + 12258.

It is an arithmetic number, because the mean of its divisors is an integer number (4250480).

Almost surely, 2^61820031 is an apocalyptic number.

61820031 is a deficient number, since it is larger than the sum of its proper divisors (40191489).

61820031 is a wasteful number, since it uses less digits than its factorization.

61820031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17455 (or 17442 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 61820031 is about 7862.5715259068. The cubic root of 61820031 is about 395.4058340270.

Adding to 61820031 its reverse (13002816), we get a palindrome (74822847).

The spelling of 61820031 in words is "sixty-one million, eight hundred twenty thousand, thirty-one".