621705961 has 16 divisors (see below), whose sum is σ = 656608768. Its totient is φ = 587865600.

The previous prime is 621705949. The next prime is 621705967. The reversal of 621705961 is 169507126.

It is a cyclic number.

It is not a de Polignac number, because 621705961 - 2¹¹ = 621703913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 621705961.

It is not an unprimeable number, because it can be changed into a prime (621705967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 307225 + ... + 309241.

It is an arithmetic number, because the mean of its divisors is an integer number (41038048).

Almost surely, 2^621705961 is an apocalyptic number.

621705961 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

621705961 is a deficient number, since it is larger than the sum of its proper divisors (34902807).

621705961 is a wasteful number, since it uses less digits than its factorization.

621705961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2272.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 621705961 is about 24934.0321849475. The cubic root of 621705961 is about 853.4832660777.

The spelling of 621705961 in words is "six hundred twenty-one million, seven hundred five thousand, nine hundred sixty-one".